Rotatable kiln having replaceable clinker ring section



Sept. 15, 1959 R. B. AITCHISON 2,904,324

ROTATABLE KILN HAVING REPLACEABLE CLINKER RING SECTION Filed Sept. 22. 1953 7 INVENTOR.

AT TOENE Patented Sept. 15, 1959 ROTATABLE KILN HAVING REPLACEABLE CLINKER RING SECTION My invention relates to a novel kiln construction and to a method of operating akiln, designed toreduce to a minimum the problems created by the formation of a sintered clinker ring in the kiln.

When large cylindrical rotary kilns are operated to roast such mineral materials as Portland cement compositions, and iron and other ores there is a tendency for some of the material to fuse partially so that the particles sinter together and to the inside walls of the kiln at a localized position to form a clinker ring which grows larger with time until it forms a dam which hinders the flow of material through the kiln. In a given kiln successive clinker rings usually form in the same locality under a given set of operating conditions.

When a clinker ring has grown to dam size it is necessary to remove it so that operation of the kiln can continue. Generally this has been accomplished by shutting down the kiln until cool enough so that workmen can gain access to the inside for drilling, blasting or otherwise eliminating the ring. Naturally this operation is costly both in manpower and shut-down time, which may sometimes amount to several days. I

In accordance with myinvention the cost in manpower and down-time is reduced greatly and the production from a kiln is greatly increased by constructing a kiln with a readily removable and replaceable section at the locality where a clinker ring tends to form. This removable section may be either between the ends, or at the end, of the kiln. When a clinker ring dam has formed in the removable section, the latter is disconnected and removed bodily from the remainder of the kiln leaving a gap. Then a duplicate replacement kiln section is moved into the gap and coupled to the remainder of the kiln. If desired, the edges of the remainder of the kiln can be dressed before installing the new kiln section. This construction and method of operation make possible elimination of a clinker ring dam rapidly and with a minimum of manpower so that the kiln only needs to beshut down for an hour or so. All operations may be remotely controlled by appropriate valves and switches located away from the heat of the kiln.

The principles of the invention will be explained in more detail below with reference to the drawings wherein:

Fig. 1 is a schematic side elevational view of a kiln embodying the invention;

Fig. 2 is a cross sectional view taken along the line 22 of Fig. 1;

Fig. 3 is a plan View, parts being omitted for simplicity, showing schematically the equipment for conveying kiln sections to and from the kiln, and for dressing the edges of the kiln;

Fig. 4 is a perspective showing a vehicle for conveying kiln sections;

Fig. 5 is a perspective view showing a vehicle carrying an edge-dressing machine;

Fig. .6 is a perspective view showing a part of a gasket for insertion between adjoining kiln sections; and

Fig. 7 is a perspective view showing a modified construction of a removable and replaceable kiln section.

Referring to Fig. 1, an inclined cylindrical rotary kiln K is mounted on idler rollers 11, 13, 15 and 17 carried by piers 19, 21, 23 and 25. Kiln K is fired by an axial burner B while being rotated about its longitudinal axis by a pair of electric motors 27 and 29 driving gears 31 and 33 which mesh with annular gears 35 and 37 mountedv peripherally of the kiln.

Kiln K comprises a pair of longitudinally spaced axially aligned shell sections 39 and 41 having non parallel spaced plane end surfaces 43 and 45 facing each other, and a removable and replaceable central wedge-shaped tubular clinker ring bearing shell section 47 fitting be-. tween and aligned axiallywith sections 39 and 41 and having non parallel end surfaces mating with the end surfaces 43 and 45.

Central section 47 is connected to the two adjoining sections 39 and 41 by two series of circumferentially arranged longitudinally movable bolts 49 and 51 on sections 39 and 41 engaging two series of welded-on ring-like keepers 53 and 55 arranged circumferentially of central section 47.

While bolts 49 and 51 can beoperated manually, I prefer to operate them automatically to avoid subjecting workmen to the intense heat of the kiln. Automatic operation advantageously is eifected by mounting the bolts slidably as pistons within two series of cylinders 57 and 59 welded on the sections39 and 41 and all simultaneously supplied with air or other pressure fluid by annular headers 61 and 63 for disengaging the bolts from their keepers, and by headers 65 and 67 for s1iding the bolts into engagement with their keepers. The

flow of pressure fluid to headers 61, 63, 65 and 67 is controlled remotely by conventional valves (not shown). Bolts 49 and 51 also can be actuated electrically-if desired.

In operation material is passed through the rotating kiln K in a conventional manner from the high end 69 to.

the low end 71 while being roasted with flame from burner B. After a while a clinker ring 73. (see Fig. 2) builds up on the refractory lining 75 in removable sec tion 47, and in time becomes so large as to obstruct the flow of material through the kiln. At this time the burner B is shut oh, the flow of material to the kiln is discontinued, and rotation is stopped (after all material has been discharged) with the kiln in such a position that the short side of the central section 47 is up and the long side down like an upwardly driven wedge.

Immediately thereafter a remotely switch controlled electrically-driven support carriage S, which has been standing off to one side of the kiln on a track 77 that passes transversely under central section 47, is moved along the track and centered under the central section by means of a remotely controlled fluid-actuated stop 79 movable up .and down into and out of engagement with the carriage.

Carriage S carries a vertical cylinder 81 within which works a fluid-actuated piston 83 carrying an arcuate supporting cradle 85 which is provided with a pair of rollers 87. Piston actuating fluid such as air or liquid is supplied to cylinder 81 by operating a remote controlling valve (not shown) so that cradle 85 is raised into supporting contact with central section 47. Then pressure fluid is admitted to the two headers 61 and 63 to disengage bolts 49 and 51 from their keepers. Section 47 is thereupon fully supported by cradle 85 which isthen lowered some distance by bleeding fluid from cylinder 81 so that section 47 becomes fully disengaged from the rest of the kiln, and is then moved oif to one side for reconditioning after cooling by movingthe carriage S along track 77 to its original position. It is apparent that the wedge shape of section 47 and its position as previously described permit the section to drop freely away from the rest of the kiln without tending to hang onto the adjoining sections.

The next step, which follows immediately as section 47 is being drawn away, is to dress up the edges of the remaining sections 39 and 41 for engagement with a replacement kiln section. This step may be omitted if the remaining edges are relatively clean and smooth. An electrically driven remotely switch controlled dressing tool carriage D, which has been held oii to one side on a spur track 89, is run onto track 77 and centered in position between the two remaining kiln sections 39 and 41, stop 79 again assuring proper positioning. Carriage D carries a vertical cylinder 91 within which works a fluid-actuated piston 93 having on its top a horizontal hollow cross piece 95 within which is journalled a rotatable horizontal shaft 97 driven by a belt 99 from a remotely switch controlled electric motor 101. Shaft 97 is connected at its opposite ends through gear boxes 103 and 105 to a pair of rotatable shafts 107 and 109 which are inclined in opposite directions upwardly away from one another. Shafts 107 and 109 in turn carry a pair of oppositely inclined plane circular heat shields '111 and 113 having the same inclinations as the planes of the edges 43 and 45 of the remaining kiln sections so as to fit quite snugly over the exposed ends of these sections for the conservation of heat during the dressing operation.

The heat shields 111 and 113 carry suitable dressing tools 115 and 117 for engaging the edges 43 and 45 and cleaning them as the shields are rotated by motor 101. As shown by way of illustration, the shields have peripheral notches 119 and 121 and the tools 115 and 117, which may be wire brushes or milling cutters are mounted on the shields so as to project into engagement with the edges to be dressed.

To dress the edges remote controlling valves admit fluid such as air or a liquid to cylinder 91 to raise shields 111 and 113 and the tools 115 and 117 into engagement with the edges 43 and 45. The motor 101 is then actuated to revolve the shields until the edges are clean. Then the piston 93 is lowered by bleeding pressure fluid from cylinder 91 and the carriage D is returned to its original position along track 77 and spur track 89.

The final step of installing a replacement kiln section 47 is then accomplished rapidly and easily by moving a second remotely switch controlled electrically driven support carriage S, which has been supporting the replacement section on the other side of kiln K from carriage S, along track 77 to a position centered be tween sections 39 and 41 (as assured by engagement of stop 79 with the carriage). Carriage S is identical with carriage S, thus having a piston-supported cradle and rollers (not shown) like those at 85 and 87 in Fig. 4. Consequently, replacement section 47' may be rotated on rollers 87 if necessary until properly adjusted to fit snugly into the space between sections 39 and 41. Thereupon the support is raised by the remotely valve controlled fluid-actuated piston and the new kiln section is in place. Replacement section 47 may be preheated, if desired, before installation.

Although it may not always be necessary, it is advantageous to place gaskets in the slight spaces between the edges of the new kiln section 47 and the adjoining edges. A suitable elongated gasket 123 of T-shaped cross section, as shown in Fig. 6, is made of a heat resistant material such as asbestos or silicone-impregnated fiberglass. Graphite rings also may be used.

After the gasket 123 has been placed, pressure fluid is admitted to the headers 65 and 67 to actuate the bolts 49 and 51 into engagement with keepers 53 and 55 and the new section 47' has then been completely integrated into the kiln.

The supporting cradle on carriage S is then lowered out of engagement with the kiln section 47 and the carriage is moved back along track 77 to its original position at one side of the kiln to remain there until it becomes necessary to replace kiln section 47.

Normal operation of kiln K is then resumed, kiln section 47 meanwhile being renovated by removing the clinker ring 73 at the convenience of the operator, so as to be ready to replace section 47 when the latter becomes fouled.

In an alternative embodiment of the invention movement of kiln sections 47 and 47 out of and into position is accomplished by a conventional universally movable overhead crane instead of carriages operating on tracks. As shown in Fig. 7, the removal and replacement of a kiln section 125 by crane is expedited by the provision of a pair of welded on heavy eyes 127 for engagement with crane hooks. These eyes 127 are located on the longest side of the wedge-shaped kiln section, and rotation of the kiln is stopped with the eyes at the top. Consequently, the wedge shape of the section makes it easy for the crane to pull it from the remainder of the kiln. In such an operation, only one crane is necessary and the removed and replacement kiln sections are stored on the ground 01'1" to one side instead of remaining on supporting carriages.

It is apparent that changes in the construction and relative arrangement of parts, and in the procedural steps of the method, can be made by those skilled in the art within the scope of the invention as defined in the claims appended hereto:

I claim:

1. A rotatable kiln comprising a pair of longitudinally spaced tubular shell sections having non parallel spaced end surfaces facing each other, a central tubular shell section fitting between said pair of shell sections and having non parallel end surfaces mating with said first-named end surfaces, all of said sections having the same diameter and forming a continuous kiln, and means connecting said shell sections together while permitting rotation thereof and operable at will to disconnect said sections whereby said central section is removable and replaceable at will in said kiln.

2. A kiln in accordance with claim 1 wherein said connecting means comprises a plurality of circumferentially arranged longitudinally movable bolts on both of said pair of shell sections, and a plurality of keepers on both ends of said central shell section for engaging said bolts, said kiln also comprising fluid-operated means for automatically actuating said bolts into and out of engagement with said keepers.

3. A rotatable kiln in accordance with claim 1, also comprising means for rotating said kiln about the longitudinal axis thereof.

4. A rotatable kiln in accordance with claim 3, also comprising means supporting each of said spaced tubular sections while permitting rotation thereof, said central section bridging the space between said spaced sections and being unsupported except by said spaced sections.

5. A kiln in accordance with claim 1 wherein said connecting means comprises circumferentially arranged mutually coacting pairs of devices carried by adjoining shell sections, and fluid operated means for automatically actuating one of each pair of said devices into and out of engagement with the other of each pair of said devices.

6. A rotatable kiln comprising a pair of longitudinally spaced tubular shell sections, means supporting each of said spaced tubular sections while permitting rotation thereof, a central section bridging the space between said spaced sections and being unsupported except by said spaced sections, all of said tubular sections having adjoining end surfaces mating with one another to form a continuous kiln, and connecting means for said shell sections holding said sections together while permitting rotation thereof and operable at will to disconnect said sections whereby said central section is removable and replaceable at will in said kiln.

7. A kiln in accordance with claim 6, also comprising support means for supporting said removable and replaceable section when disconnected, and means for transporting said support means and said removable and replaceable kiln section therewith away from position in said kiln.

8. A kiln in accordance with claim 7, wherein said support means includes rotatable supporting mechanism whereby said kiln section is rotatable about the longitudinal axis thereof on said support.

9. A kiln in accordance with claim 7 wherein said support means comprises a carriage movable transversely under said kiln, and a cradle carried by said carriage for receiving said kiln section.

10. A kiln in accordance with claim 9 wherein said support means also comprises mechanism for raising and lowering said cradle.

11. A rotatable kiln in accordance with claim 6 wherein said connecting means comprises a plurality of circumferentially arranged longitudinally movable bolts on said spaced shell sections, and a plurality of keepers on both ends of said central section for engaging said bolts, said bolts being slidable into and out of said keepers.

12. A kiln in accordance with claim 11, also comprising fluid-operated means for automatically actuating said bolts into and out of engagement with said keepers.

References Cited in the file of this patent UNITED STATES PATENTS 769,742 Haldeman Sept. 13, 1904 813,490 Edison Feb. 27, 1906 851,352 Hibbins Apr. 23, 1907 891,327 Clark et a1 June 23, 1908 977,324 Nichols Nov. 29, 1910 1,188,567 Singer June 27, 1916 1,242,111 Hopkins Oct. 2, 1917 1,333,645 Walker Mar. 16, 1920 1,946,971 Harter Feb. 13, 1934 2,069,768 Millan Feb. 9, 1937 2,458,472 Irwin Jan. 4, 1949 2,490,233 Schildmeier Dec. 6, 1949 2,638,333 Hess May 12, 1953 FOREIGN PATENTS 209,561 Germany May 5, 1909 266,368 Great Britain Dec. 8, 1927 8,662 Great Britain Apr. 15, 1907 341,511 Italy June 27, 1936 

